Stabilization of photographic developers



Patented Jan. 13, 1953 STABILIZATION OF PHOTOGRAPHIC DEVELOPERS Harold D. Russell and Grant M. Haist, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a. corporation of New Jersey No Drawing.

Application March 28, 1951,

Serial No. 218,071

18 Claims.

This invention relates to photographic developers and more particularly to photographic developers possessing improved stability.

It is Well known that photographic developers are somewhat unstable readily undergoing oxidation, some to a greater extent than others, during use in the development of silver images in silver halide emulsion layers, and even while such developers are not in use. In the latter case, undesirable oxidation takes place even in closed containers presumably due to the presence of limited quantities of air over or dissolved in the developing solution. Developing solutions particularly susceptible to such oxidation are the hydrazine-containing developers such as disclosed in the Ives U. S. patent application, Serial No. 192,380, filed October 26, 1950, now U. S. Patent No. 2,588,982 granted March 11, 1952, and disclosed in the Bean et al. U. S. patent application, Serial No. 218,072, filed concurrently herewith. These developers contain any of a number of hydrazine compounds, such as phenyl and naphthyl hydrazines, for example, 1-naphthylhydrazine-7-sulfonic acid and p-(B-methylsulfonamidoethyl)-phenylhydrazine, in addition to the usual silver halide developing agent, alkali, antifoggant, etc.

These hydrazine-containin developers with which our invention is concerned, are used for the development of direct positive images in exposed internal latent image types of emulsions, such as described in the mentioned copending inventions and particularly described in the Falleson U. S. Patent 2,497,375, and Davey and Knott U. S. patent application, Serial No. 82,914 filed March 22, 1949, now Patent No. 2,592,250.

We have discovered that the tendency for these hydrazine-containing developers to oxidize is materially reduced if diglycolic acid or its alkali metal salts are incorporated into the developer. Further, we have discovered that the efiicacity of diglycolic acid or its salts is considerably increased if the acid is employed in developers containing an alkali metal orthophosphate. The alkali metal polyphosphates do not appear to be effective.

Accordingly, one object of our invention is to provide hydrazine-containing developing solutions possessing improved stability. Another object is to provide packaged dry mixtures of developing chemicals containing diglycolic acid or its salts as stabilizing agents for hydrazine-containing developing solutions made by dissolving the packaged chemicals in water. A further ob.- ject is to describe the use of such developing solutions. Other objects will become apparent by consideration of the following description of our invention.

The objects of our invention are accomplished in part by the incorporation of diglycolic acid or its alkali metal salts into a hydrazine-containing composition.

The amount of diglycolic acid used in such developers is dependent for the most part upon the propensity of the developer toward oxidation. The particular developing agent, the amount of sulfite, antifoggant and alkali present, also influence the rate of developer oxidation. However, we use from about 5 to 50 grams, preferably 5 to 15 grams, per liter of developing solution of diglycolic acid or its alkali metal salts. The hydrazine content of the developing solutions can be varied from about 0.5 to 10 grams per liter. However, the limiting concentration for the hydrazine content of the developing solutions is determined for the most part by the solubility of the particular hydrazine under consideration. Since the developer compositions are alkaline, hydrazines containing no alkali solubilizing groups, such as sulfonic acid groups, possess limited solubility in the developer solutions and may be considered to be soluble to the extent of only about 4 grams per liter of developing solution. However, the hydrazines are very efiective at these concentrations in the developing solutions of the invention. Hydrazines such as l-naphthylhydrazine-7-sulfonic acid, are soluble in the alkaline developing solutions to the extent of about 10 grams per liter of developing solution.

When the orthophosphates are incorporated into the developing solutions, we can use from about 5 to 200 grams, preferably 5 to grams, per liter of developing solution.

The following developer compositions are representative of those useful in our invention:

Developer No.

I II III IV Monomethyl-p-aminophenol sulfate grams. 5. 0 5.0 5.0 5. 0 Hydroqumone do 10.0 10. 0 l0. 0 20. 0 Sodium sulfite do 75.0 75.0 75.0 75. 0 Tnsodlum phosphate (cryst.) .do. 75.0 p (fl-Methylsulfonamido-ethyl) -phenylhydrazine hydrochloride gra1ns 2.0 2.0 2.0 2. 0 Sodium hydroxide..-" .do..-. 16.0 11.0 40. 0 40. 0 5-ll/Iethylbenzptr1azole. do 0.2 0. 2 0. 2 0. 4 Diglycohc acid .do..-. 13.4 13. 4 53. 4 45. 0 Water to -.liters. l l 1 l In the above developer formula No. VI, the mixture of hydrazines represents a commercial material containing approximately equal amounts of the 1-6 and 1-7 isomeric hydrazines.

It will be noted that the above developer compositions are unique among photographic developers as a whole. By virtue of the presence of hydrazine compounds in the developer compositions, the developers will yield direct positive images in the internal latent image types of emulsion for which they are designed. If the hydrazine compound is not present in the developer, no positive image is obtained in these emulsions.

Diglycolio acid is unique in its stabilizing eifect on the developers of the invention. For example, a related compound, glycolic acid, is relatively ineffective in stabilizing the hydrazine-containing developers, as much as 100 grams per liter of glycolic acid being required before any stabilizing efiect is appreciable, Whereas we obtained optimum results when utilizing from about to grams of diglyoolic acid per liter of developing solution. In addition, when phosphate is added to a developer composition containing hydrazine and glycolic acid, no improvement in stabilizing effect of glycolic acid is noted. To the contrary, when the phosphate is added to a developer composition containing hydrazine and diglycolic acid, a marked improvement in the stabilizing effect of diglycolic acid is obtained.

Hydrazines useful in our developer compositions, in addition to those set forth in the above examples, can be selected from those disclosed in the mentioned Ives and Bean et a1. copending inventions, e. g., the halogenated arylhydrazines and the sulionated arylhydrazines, particularly the monoand disulfonated aand fi-naphthylhydrazines. As is apparent, one or more hydrazines can be used in the developer compositions. The hydrazine can be incorporated into the developer compositions either in the form of the free base o preferably in the form of an. acid salt, such as the hydrochloride, in the case of non-sulfonated hydrazines. When the sulfonated hydrazines are used, the acid or salt forms can be employed. When hydrazines are used whose free base forms are liquids at normal temperatures, we prefe to use the salts of such hydrazines in dry mixtures of chemicals which are packaged for the trade for use in dissolving in water to form a developer solution, because the hydrazine bases in liquid form are difficult to incorporate into the packaged compositions. Accordingly, the solid forms of the hydrazines are preferred in the dry packaged developer compositions.

The phosphates useful in the developer compositions of the invention include the water-soluble alkali metal orthophosphates such as trisodium phosphate, sodium dihydrogen phosphate and disodium phosphate. The Henn U. S. patent application Serial No. 218,073, filed concurrently herewith, relates to the use of diglycolic acid in developers alone o in conjunction with an alkali metal polyphosphate for the purpose of sequestering calcium salts in photographic developers.

The following dry mixtures of chemicals are typical of those useful in our invention as dry packaged chemicals suitable for dissolving in water to form one liter of developing solution:

Example 1 Compartment A: Grams Monomethyl-p-aminophenol sulfate 50 Hydroquinone 10.0 p-;8-Methylsulfonamidoethyl phenylhydrazine hydrochloride 2.0 5-methy1benzotriazo1e 0.2 Compartment B:

Sodium sulfite 75.0 Diglycolic acid 13.4 Compartment C; Trisodium phosphate 75.0 Compartment D: Sodium hydroxide 16.0

The sodium hydroxide in the above composition is varied as required so as to obtain a developer solution having a pH of from about 11 to 12, preferably 11.5, when the ingredients are dissolved in water.

Example 2 Compartment A: Grams Monomethyl-p-aminophenol sulfate 5.0 Hydroquinone 10.0

1-naphthylhydrazine-7-sulfonic acid 3.0 E-methyl benzotriazole 0.2 Sodium sulfite (desiccated) 75.0 Sodium phosphate (dibasic, dry powder) 25.0 Diglycolic acid 15.0

Compartment B: Sodium hydroxide 19.0

The sodium hydroxide in this composition is varied as required so as to obtain a developer solution having a pH of from about 10.5 to 11.5, preferably 11.0, when the ingredients are dissolved in water. Presumably, when a naphthylhydrazine sulfonic acid is used, the pH range can be lower without adversely affecting developer properties. Some derivatives of naphthylhydrazine, such as 4-bromo-1-naphthylhydrazine-7-sulfonic acid, develop satisfactorily at a pH of 10.0.

In accordance with the above examples it is desirable to adjust the pH of the developers within the range of about 10.5 to 12 to obtain the best results from developing the exposed internal latent image types of emulsions.

The method of using our developer compositions is not especially critical and a more complete description of the useful emulsions and method of using the developers of the invention may be obtained by reference to the copending Ives and Bean et al. inventions above-mentioned.

We claim:

1. An alkaline photographic developing solution comprising a silver halide developer, a hydrazine, and a compound selected from the group consisting of diglyoolic acid and its alkali metal salts.

2. An alkaline photographic developing solution comprising a silver halide developer, a hydrazine, a water-soluble alkali metal orthophosphate, and a compound selected from the group consisting of diglycolic acid and its alkali metal salts.

3. An alkaline photographic developing solution comprising a silver halide developer, a naphthylhydrazine, a water-soluble alkali metal orthophosphate, and a compound selected from the group consisting of diglycolic acid and its alkali metal salts.

4. An alkaline photographic developing solution comprising a silver halide developer, a water-soluble alkali metal orthophosphate, a compound selected from the group consisting of naphthylhydrazine sulfonic acids and alkali metal salts thereof.

5. An alkaline photographic developing solution comprising a silver halide developer, a a Water-soluble alkali metal orthophosphate, a compound selected from the group consisting of diglycolic acid and its alkali metal salts, and a compound selected from the group consisting of l-naphthylhydrazine-7-sulfonic acid and alkali metal salts thereof.

6. An alkaline photographic developing solution comprising a silver halide developer, a water-soluble alkali metal orthophosphate, a compound selected from the group consisting of diglycolic acid and its alkali metal salts, and a compound selected from the group consisting of 1-naphthylhydrazine-6-su1fonic acid and alkali metal salts thereof.

'7. An alkaline photographic developing solution comprising a silver halide developer, from about 5 to 200 grams per liter of a water-soluble alkali metal orthophosphate, from about 5-50 grams per liter of a compound selected from the group consisting of diglycolic acid and its alkali metal salts, and from about 0.5 to 10 grams per liter of a compound selected from the group consisting of naphthylhydrazine sulfonic acids and alkali metal salts thereof.

8. A photographic developer in dry form comprising a silver halide developer, an alkaline material, a solid hydrazine compound and a compound selected from the group consisting of diglycolic acid and its alkali metal salts.

9. A photographic developer in dry form comprising a silver halide developer, suflicientaj alkaline material to produce an alkaline solution, sufiicient solid hydrazine compound to produce from about 0.5 to 10 grams per liter in solution, and a sufiicient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

10. A photographic developer in dry form comprising a silver halide developer, suiiicient alkaline material to produce an alkaline solution, sufficient naphthylhydrazine compound to produce from about 0.5 to 10 grams per liter in solution, and a sufficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

11. A photographic developer in dry form comprising a silver halide developer, sufficient alkali metal orthophosphate to produce from about 5-200 grams in solution, suiiicicnt alkaline material to produce an alkaline solution, sufficient solid hydrazine compound to produce from about 0.5 to 10 grams per liter in solution, and a sufii= cient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

12. A photographic developer in dry form cornprising a silver halide developer, sufficient alkali metal orthophosphate to produce from about 5-200 grams in solution, sufficient alkaline material to produce an alkaline solution, sufficient naphthlyhydrazine compound to produce from about 0.5 to 10 grams per liter in solution, and a sufficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in Water.

13. A photographic developer in dry form comprising a silver halide developer, sufiicient alkali metal orthophcsphate to produce from about 5-200 grams in solution, suflicient alkaline material to produce an alkaline solution, sufiicient naphthylhydrazine sulfonic acid compound to produce from about 0.5 to 10 grams per liter in solution, and a sufficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

14. A photographic developer in dry form comprising a silver halide developer, suifioient alkali metal orthophosphate to produce from about 5-200 grams in solution, sufiicient alkaline material to produce an alkaline solution, sufficient 1- naphthylhydrazine-7-sulfonic acid compound to produce from about 0.5 to 10 grams per liter in solution, and a sufficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

15. An alkaline photographic developing solution comprising a silver halide developer, a phenylhydrazine, a water-soluble alkali metal orthophosphate, and a compound selected from the group consisting of diglycolic acid and its alkali metal salts.

16. An alkaline photographic developing solution comprising a silver halide developer, p- 13-methylsulfonamidoethyl) -pheny1hydrazine, a water-soluble alkali metal orthophosphate, and a compound selected from the group consisting of diglycolic acid and its alkali metal salts.

17. A photographic developer in dry form comprising a silver halide developer, sufiicient alkaline material to produce an alkaline solution, suiilcient phenylhydrazine compound to produce from about 0.5 to 10 grams per liter in solution, and a sufficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

18. A photographic developer in dry form comprising a silver halide developer, suficient alka line material to produce an alkaline solution, suflicient p- ({3-methylsulfonamidoethyl) -phenylhydrazine to produce from about 0.5 to 10 grams per liter in solution, and a suficient amount of a compound selected from the group consisting of diglycolic acid and its alkali metal salts to produce from about 5 to 50 grams per liter in solution, when the mixture is dissolved in water.

HAROLD D. RUSSELL. GRANT M. HAIST.

No references cited. 

1. AN ALKALINE PHOTOGRAPHIC DEVELOPING SOLUTION COMPRISING A SILVER HALIDE DEVELOPER, A HYDRAZINE, AND A COMPOUND SELECTED FROM THE GROUP CONSISTING OF DIGLYCOLIC ACID AND ITS ALKALI METAL SALTS. 